Spring File Download
Let's create a simple file download control and service.
Source
Controller
This is the controller part.
Simply receive a form object and void it, so there is no direct return.
// File Download
@GetMapping("/file/{path}")
public void getFileDownload(HttpServletResponse response, @PathVariable String path) {
fileService.download(response, path);
}Service
This is the part that actually sends the file. Pass the file object to the response with getOutputStream.
// download
public void download(HttpServletResponse response, String path) {
String filePath = "C:/tmp/file";
String fileName = path.split("__")[1];
String orgPathFile = String.format("%s%s%s", filePath, File.separator, path);
try {
// Exception handling if there is a space in the file name (-> _ prevention)
fileName = URLEncoder.encode(fileName, StandardCharsets.UTF_8);
fileName = fileName.replaceAll("\\+", "%20");
byte[] files = FileUtils.readFileToByteArray(new File(orgPathFile));
response.setContentType("application/octet-stream");
response.setContentLength(files.length);
response.setHeader("Content-Disposition","attachment; fileName=\"" + fileName + "\";");
response.setHeader("Content-Transfer-Encoding","binary");
response.getOutputStream().write(files);
response.getOutputStream().flush();
response.getOutputStream().close();
} catch (IOException e) {
System.out.println(e.getMessage());
}
}Example
Other examples
Spring server-side upload
Spring server-side download
Client JavaScript Fetch upload
Client JavaScript Fetch download